---
title: Add reading time
description: Build a remark plugin to add reading time to your Markdown or MDX files.
i18nReady: true
type: recipe
---

import PackageManagerTabs from '~/components/tabs/PackageManagerTabs.astro'

Create a [remark plugin](https://github.com/remarkjs/remark) which adds a reading time property to the frontmatter of your Markdown or MDX files. Use this property to display the reading time for each page.

## Recipe

1. Install Helper Packages

  Install these two helper packages:
  - [`reading-time`](https://www.npmjs.com/package/reading-time) to calculate minutes read
  - [`mdast-util-to-string`](https://www.npmjs.com/package/mdast-util-to-string) to extract all text from your markdown

  <PackageManagerTabs>
    <Fragment slot="npm">
    ```shell
  npm install reading-time mdast-util-to-string
    ```
    </Fragment>
    <Fragment slot="pnpm">
    ```shell
  pnpm add reading-time mdast-util-to-string
    ```
    </Fragment>
    <Fragment slot="yarn">
    ```shell
  yarn add reading-time mdast-util-to-string
    ```
    </Fragment>
  </PackageManagerTabs>

2. Create a remark plugin.

  This plugin uses the `mdast-util-to-string` package to get the Markdown file's text. This text is then passed to the `reading-time` package to calculate the reading time in minutes. 

  ```js title="remark-reading-time.mjs"
  import getReadingTime from 'reading-time';
  import { toString } from 'mdast-util-to-string';

  export function remarkReadingTime() {
    return function (tree, { data }) {
      const textOnPage = toString(tree);
      const readingTime = getReadingTime(textOnPage);
      // readingTime.text will give us minutes read as a friendly string,
      // i.e. "3 min read"
      data.astro.frontmatter.minutesRead = readingTime.text;
    };
  }
  ```

3. Add the plugin to your config:

  ```js title="astro.config.mjs" "import { remarkReadingTime } from './remark-reading-time.mjs';" "remarkPlugins: [remarkReadingTime],"
  import { defineConfig } from 'astro/config';
  import { remarkReadingTime } from './remark-reading-time.mjs';

  export default defineConfig({
    markdown: {
      remarkPlugins: [remarkReadingTime],
    },
  });
  ```

  Now all Markdown documents will have a calculated `minutesRead` property in their frontmatter. 

4. Display Reading Time

  If your blog posts are stored in a [content collection](/en/guides/content-collections/), access the `remarkPluginFrontmatter` from the `entry.render()` function. Then, render `minutesRead` in your template wherever you would like it to appear.

  ```astro title="src/pages/posts/[slug].astro" "const { Content, remarkPluginFrontmatter } = await entry.render();" "<p>{remarkPluginFrontmatter.minutesRead}</p>"
  ---
  import { CollectionEntry, getCollection } from 'astro:content';

  export async function getStaticPaths() {
    const blog = await getCollection('blog');
    return blog.map(entry => ({
      params: { slug: entry.slug },
      props: { entry },
    }));
  }

  const { entry } = Astro.props;
  const { Content, remarkPluginFrontmatter } = await entry.render();
  ---

  <html>
    <head>...</head>
    <body>
      ...
      <p>{remarkPluginFrontmatter.minutesRead}</p>
      ...
    </body>
  </html>
  ```

  If you're using a [Markdown layout](/en/guides/markdown-content/#markdown-and-mdx-pages), use the `minutesRead` frontmatter property from `Astro.props` in your layout template.

  ```astro title="src/layouts/BlogLayout.astro" "const { minutesRead } = Astro.props.frontmatter;" "<p>{minutesRead}</p>"
  ---
  const { minutesRead } = Astro.props.frontmatter;
  ---

  <html>
    <head>...</head>
    <body>
      <p>{minutesRead}</p>
      <slot />
    </body>
  </html>
  ```
